To evaluate the effect of hydroxyapatite coating, two same shape cementless stems were compared in this randomized control trial study. Between May 2003 and February 2010, 88 patients had a primary cementless total hip arthroplasty with two different types of cementless stems. Forty-three patients had Proarc stems (P group) (Kyocera Medical, Osaka, Japan), and Forty-five patients had Proarc HA stems (HA group) (Kyocera Medical, Osaka, Japan) which was coated with thin (20 micrometer) hydroxyapatite on Proarc rough porous coating. Gender distribution, average age at surgery, average weight and average follow-up period were same in the two groups. The average follow-up period was 8.5 years (range, 5 to 13 years). The average age at the time of surgery was 63 years. Porous acetabular shells and highly crosslinked polyethylene liners made by Kyocera Medical corporation were implanted into all hips. Stems were implanted with a modified Hardinge surgical approach without trochanteric osteotomy. Harris Hip Score was used for clinical evaluation. Post-op radiographs of these patients were evaluated. Fisher's exact probability test was used for statistical analysis. P values of less than 0.05 were considered to be significant.Introduction
Methods
Deformity after femoral osteotomy varies between patients. Some researchers reported good results when using cemented stems for the hips after femoral osteotomy, but there are many disadvantages that obstruct ideal fixation using cemented stems. Therefore, we developed cementless custom-made stems and inserted those using a computed tomography (CT) –based navigation system Eighteen dysplastic hips of 15 patients after intertrochanteric osteotomy were investigated in the present study. Individual computed tomography data were used to manufacture cementless custom-made femoral stems out of Ti-6Al-4V. The proximal 1/3 of each stem was coated using porous coating covered with hydroxyapatite coating. The stems were inserted using a CT-based fluoro navigation system for accuracy of insertion. The average patient age at time of surgery was 66 years, and the average follow-up period was 3.5 years.Introduction
Methods
Hemophilia arthropathy often occurs in the ankle, knee and elbow. In contrast, hemophilic arthropathy in the hip is rare. We report short-term results of total hip arthroplasty (THA) in patients with hemophilia. Four primary THAs performed in four hemophilic patients from 2007 to 2015 were reviewed retrospectively. Two patients underwent cementless THA, and two patients had cemented THA. All patients had hemophilia A, and clotting factor replacement was performed perioperatively. Blood loss, surgery duration, complications, pre- and post-operative range of motion, and the pre- and post-operative Japanese Orthopedic Association (JOA) score were assessed.Introduction
Method
The approach in total knee arthroplasty (TKA) with severe valgus deformity is controversial. The lateral parapatellar approach has been proposed for several years, but surgical technique of this approach was unusual and difficult. Therefore, we have consistently been selected medial parapatellar approach (MPP) for all cases. In this study, we investigated the short term results of TKA for severe valgus deformity with MPP about clinical and radiographic assessment. Seven knees in seven cases of severe valgus knees with stand femorotibial angle (FTA) less than 160 degrees were enrolled. Osteoarthritis were 6 cases, hemophilic arthropathy was 1 case and no rheumatoid arthritis case. There were 6 female and 1 male, and mean age was 63.6 years (41–75 years). Duration of follow up ranged 3 months to 22.5 months, with mean of 10.9 months. We compared alignment on standing radiograph, range of motion (ROM), the Japanese Orthopaedic Association (the JOA) score for osteoarthritic knee pre/postoperatively, and examined post operative complication retrospectively.Objectives
Methods
Bilateral leg alignment should be equal for preventing leg length discrepancy and diminishing limping in walking. The candidates for total knee arthroplasty (TKA) sometimes image bilateral TKA seems to get completely same shape and alignment of legs. The query that bilateral TKA, staged in a day and by one surgeon, has an advantage to reconcile one side alignment and component setting to another side, was investigated. This retrospective investigation enrolled 408 knees of 204 patients (74 years old on average) underwent one day TKA and 48 knees of 24 cases (73 years old on average) underwent two days TKA. There were no history of trauma and surgery on both legs and no other obvious features. All components were same (Vanguard PS TKA, Biomet Inc. Warsaw IN). Surgical procedure is single (modified gap technique) with intramedullar rod for the femur and extramedullar system for the tibia without navigation system and patient specific instrumentation (PSI). Postoperative femorotibial angle (FTA), α, β, γ, δ angles were computed and the absolutes of differences between right and left were analyzed. (two sample t test)Background
Materials and methods
To utilize existing cancellous bone for initial stability, custom-made stems were implanted without reaming and rasping. This study reviewed the results of this non-reaming technique. One hundred and fifty-three hips (138 patients) were followed-up for an average of 12 years (range, 8 to 18). Average age at the surgery was 59 (range, 19 to 78). Seventy percent of the etiologies were dysplastic hips including 17 hips after femoral osteotomy. The Ti-6Al-4V stems were designed using CT data and directly inserted into the femora without reaming and rasping. The stems were coated with hydroxyapatite on the porous coating at proximal 1/3. Harris hip score was used for clinical evaluation.Introduction
Methods
It is essential to investigate the tribological maturation of tissue-engineered cartilage that is to be used in medical applications. The frictional performances of tissue engineered cartilage have been measured using flat counter surfaces such as stainless steel, glass or ceramics. However, the measured friction performances were significantly inferior to those of natural cartilage, likely because of cartilage adhesion to the counter surface. Tamura et al. reported that a poly (2- methacryloyloxyethyl phosphoryl-choline (MPC)) grafted surface shows low friction coefficient against cartilage without the adhesion to be equivalent to those for natural cartilage-on-cartilage friction. [1] On the other hand, Yamamoto et al. reported that applying a relative sliding movement had a potential to alter the expression of tribological function of regenerated cartilage of chondrocytes. [2] In this paper, the effects of the relative sliding movement on the expression of bone marrow stromal cells (BMSC)s were investigated using the poly(MPC) grafted surface as a counter surface. BMSCs seeded onto fibroin sponge scaffolds were cultured by using the stirring chamber system (Figure 1), which can apply a relative tribological movement to the surface of the specimens. Three culture conditions were applied (dynamic in stirring chamber as frequency as 40 min [D1], as 40 sec [D2] and static in stirring chamber group [S]). The specimens were set into stirrer on a poly(MPC) grafted surface (MPC polymer coated surface, SANSYO). As a counter surface in friction tests, the poly(MPC) grafted surface was prepared by atom transfer radical polymerization, and the regenerated cartilage was prepared by seeding 5×105 cells (BMSCs from rat bone marrow) onto fibroin sponge scaffolds (8 mm diameter and 1 mm thickness) and by 14 days culture.Introduction
Material and methods
